Under the guidance, companies are allowed to use the spot yield curve, which is used for measuring pension assets and liabilities, for 2009, regardless of what they used in prior years, according to the council. In addition, the council said the guidance clarifies that the yield curve can be used for any "applicable month"—not the month preceding the plan year, as originally proposed.

"In the short run, this guidance will allow many employer-plan sponsors to more reasonably measure the value of their pension plan liabilities into the future while continuing to ensure that these plans will be fully funded and provide all promised benefits," Klein said, noting that additional guidance and legislation are needed in the future.